Motor-driven vehicles generally include an engine with a transmission for driving the wheels of the engine. Often the engine has a significant excess of power available to drive auxiliary systems that are required to perform the vehicle's intended services. A power take-off (PTO) system typically delivers rotary power from the engine to auxiliary systems via a PTO shaft that allow the auxiliaries to draw power from the engine. In some cases, auxiliary systems, such as hydraulic systems for running non-drive components of industrial, agricultural and construction vehicles, require substantial amounts of power from the engine. In many instances, the space available within the engine compartment is limited, which creates a design challenge to implement a PTO system that can deliver enough power to drive auxiliary systems that require up to all the power of the engine.
PTO systems may be positioned so as to take power from the front end of the engine crankshaft (front drive PTO) or the rear end of the engine crankshaft (rear drive PTO). For front drive PTO, an integrated gear-driven or a chain-driven PTO system is often used to take power from the engine crankshaft. These systems, however, are usually bulky, integral parts of the engine that are difficult to fit into a vehicle that requires a compact engine configuration, such as a forklift. These PTO systems are also difficult to service, and deliver only a fraction of the power supplied from the associated engine.
Accordingly, the inventors have identified a need in the art for a more robust front drive PTO system for proving power to auxiliary systems in a compact environment.
Unless otherwise indicated herein, the foregoing description in this section is not prior art to the claims in this application and is not admitted to be prior art by inclusion in this section.